Sensor apparatus for process measurement

Abstract

A sensor apparatus for transmitting electrical pulses from a signal line into and out of a vessel to measure a process variable. The sensor apparatus includes a mounting section configured to be coupled to the vessel, a conductive probe element, a dielectric insert located within the mounting section, a conductive pin coupled to the top end of the probe element, and an electrical connector coupled to the conductive pin. The conductive probe element has a predetermined diameter and is formed to include a section having a reduced diameter adjacent a top end of the probe element and a tapered section providing transition from the probe element to the reduced diameter section. The dielectric insert includes an inwardly tapered section to prevent movement of the probe element in a direction toward the mounting section and an outwardly tapered section. The conductive pin has a larger diameter than the diameter of the reduced-diameter section of the probe element to engage the outwardly tapered section of the dielectric insert and to prevent movement of the probe element in a direction away from the mounting section. The electrical connector is configured to couple the signal line to the probe element through the conductive pin.

What is claimed is: 
     
       1. A sensor apparatus for transmitting electrical pulses from a signal line into and out of a vessel to measure a process variable, the sensor apparatus comprising: a mounting section configured to be coupled to the vessel;   a conductive probe element having a predetermined diameter, the probe element being formed to include a section having a reduced diameter adjacent a top end of the probe element and including a tapered section providing transition from the probe element to the reduced diameter section;   a dielectric insert located within the mounting section, the dielectric insert including an inwardly tapered section to prevent movement of the probe element in a direction toward the mounting section and an outwardly tapered section;   a conductive pin coupled to the top end of the probe element, the conductive pin having a larger diameter than the diameter of the reduced-diameter section of the probe element to engage the outwardly tapered section of the dielectric insert to prevent movement of the probe element in a direction away from the mounting section; and   an electrical connector coupled to the pin, the connector being configured to couple the signal line to the probe element through the conductive pin.   
     
     
       2. The apparatus of claim 1 wherein at least one of the electrical connector and the conductive pin includes an aperture and the other of the electrical connector and conductive pin slidably engages the aperture to permit movement of the probe element relative to the mounting section. 
     
     
       3. The apparatus of claim 1, wherein the conductive pin includes a conically shaped transition section. 
     
     
       4. The apparatus of claim 3, wherein the conical shaped section has a first diameter adjacent the electrical connector and a second diameter adjacent the probe element, the second diameter being larger than the first diameter. 
     
     
       5. The apparatus of claim 1, further comprising a second dielectric insert coupled to the mounting section above the first dielectric insert to retain the first